In drill stem testing where a temporary completion is made of an earth formation interval that has been intersected by a well bore, it is desirable to use "full-bore" test tools that are constructed in a manner to provide straight vertical access through the tools so that various wireline devices such as perforating guns and the like can be run without removing the equipment from the well. In accordance with typical drill stem testing practice, a packer and a normally closed test valve are lowered into the well bore on a pipe string, and the packer is set to isolate the interval to be tested from the hydrostatic head of fluid in the well thereabove. The test valve, which may be a ball or flapper valve, is opened to draw down the pressure in the interval so that cognate formation fluids will enter the well bore, and then the valve is closed to permit the pressure of fluids to build-up while measurements are made as a function of time and are recorded on a gauge. The data is, of course, of considerable value in connection with subsequent completion decisions as will be recognized by those skilled in the art.
A readout of the data at the surface as the test proceeds is highly desirable from the standpoint of being able to optimize the durations of the flow and shut-in periods, as well as to continuously monitor downhole tool performance. Transmission of the data to the surface generally requires that an electric wireline be positioned in the pipe string, and an electrical connection made with an output terminal in the tool string. When the data has been transmitted, the connection is released so that the wireline can be removed from the pipe string prior to removal of the test tools from the well.
An apparatus for use in making an electrical connection in a full-bore test tool string is disclosed in U.S. application Ser. No. 422,246, Guidry et al, assigned to the assignee of this invention. This structure, while being basically sound in concept, is considered to have a number of disadvantages. The arms of the running tool extend upwardly on the body, and are susceptible to getting stuck in the pipe string should they accidentally open up as the tool is being withdrawn therefrom. Thus it is possible that the arms could be broken off and dropped into the pipe, which would require a time consuming and somewhat expensive fishing job for their removal. Also, a fairly precise degree of alignment of the arms is required to make proper electrical contact, in the absence of which the male pins employed in the system can be bent and cause shorting or other malfunction. Moreover, the apparatus described in the application may be considered to be structurally complicated and somewhat unreliable in operation.
It is accordingly the general object of the present invention to provide a new and improved electrical connector apparatus useful in drill stem testing with full bore testing tools.
Another object of the present invention is to provide a new and improved apparatus of the type described which does not require precise alignment in order to make proper electrical contact.
Yet another object of the present invention is to provide a new and improved electrical connector apparatus of the type described which is less complicated, and more reliable in operation, than prior devices.